The Scarecrow (SCR) transcription factor plays a crucial role in root cell radial patterning and is required for maintenance of the quiescent centre and differentiation of the endodermis. In response to phosphorus (P) deficiency, white lupin (Lupinus albus L.) root surface area increases some 50-fold to 70-fold due to the development of cluster (proteoid) roots. Previously it was reported that SCR-like expressed sequence tags (ESTs) were expressed during early cluster root development. Here the cloning of two white lupin SCR genes, LaSCR1 and LaSCR2, is reported. The predicted amino acid sequences of both LaSCR gene products are highly similar to AtSCR and contain C-terminal conserved GRAS family domains. LaSCR1 and LaSCR2 transcript accumulation localized to the endodermis of both normal and cluster roots as shown by in situ hybridization and gene promoter::reporter staining. Transcript analysis as evaluated by quantitative real-time-PCR (qRT-PCR) and RNA gel hybridization indicated that the two LaSCR genes are expressed predominantly in roots. Expression of LaSCR genes was not directly responsive to the P status of the plant but was a function of cluster root development. Suppression of LaSCR1 in transformed roots of lupin and Medicago via RNAi (RNA interference) delivered through Agrobacterium rhizogenes resulted in decreased root numbers, reflecting the potential role of LaSCR1 in maintaining root growth in these species. The results suggest that the functional orthologues of AtSCR have been characterized.

Introduction: Endophytic fungi are becoming an important source of new natural bioactive products. Many interesting endophytic fungi have been isolated from traditional medicinal plants. Crocus sativus L. (saffron) is one of the most expensive and rarest spices in the world, used as a dye, aroma and for medicinal purposes. This study reports on the molecular characterization of endophytic fungi isolated from roots of saffron plants growing in Taliouine-Morocco, and the examination of the antibacterial and antioxidant activities of secondary metabolites extracted from these endophytes. Methods and Material: The fungi were isolated from sterilized saffron root fragments and identified using internal transcribed spacer (ITS) rRNA gene sequence analysis. Three endophytes were fermented and extracted with ethyl acetate (EtOAc) and chloroform (CHCl 3). The antibacterial activity of fungi extracts was evaluated using the Agar Diffusion Method against six strains, Bacillus sp., Stenotrophomonas sp., Pseudomonas putida, Pantoea sp., Luteibacter sp. and Escherichia coli. The antioxidant activity was tested by using the α,α-diphenyl-β-picrylhydrazyl (DPPH) analysis and β-Carotene bleaching test (BCBT) methods. Results: Sixty fungal isolates were recovered and purified from saffron roots. ITS rDNA sequences were 99-100% identical to three different species: Rhizopus oryzae, Aspergillus fumigatiaffinis and Aspergillus niger. Both Rhizopus oryzae extracts had high antibacterial activity against most of the bacteria tested, while Aspergillus niger and Rhizopus oryzae extracts showed an antioxidant capacity using DPPH and BCBT methods, respectively. Conclusion: The fungal endophytes inhabiting saffron roots could be a potential source of natural plant bioactive secondary metabolites especially for antibacterial and antioxidant purposes.